AQUA-1: Drinking water Certified Reference Material for trace metals and other constituents

Product documentation

The following tables show those constituents for which certified, reference and information values have been established for this river water certified reference material (CRM).

The expanded uncertainty (UCRM) in the certified value is equal to U = kuc where uc is the combined standard uncertainty calculated according to the JCGM Guide [1] and k is the coverage factor. A coverage factor of two (2) was applied for all elements. It is intended that UCRM accounts for every aspect that reasonably contributes to the uncertainty of the measurement. The density of AQUA-1 is 0.9991 g/mL at 21 oC.

Intended use

This certified reference material is primarily intended for use in the calibration of procedures and the development of methods used for the analysis of water for trace metals. A minimum sample volume of 10 mL is recommended.

Storage and sampling

It is recommended that the material be stored at +4 oC temperature. The bottles should be opened only in a clean area with precautions taken against contamination during sampling.

Uncertainty

Included in the overall combined uncertainty estimate (uc) are uncertainties in the batch characterization (u,char), uncertainties related to possible between-bottle variation (uhom), and uncertainties related to inconsistency between the various measurement methods (umethod). Expressed as standard uncertainties, these components are listed in Table 3.

Table 3: Uncertainty components for AQUA-1

Element

uc,μg/kg

uchar,μg/kg

uhom,μg/kg

umethod,μg/kg

aluminium

0.8

0.8

0.0

0.0

antimony

0.0028

0.0028

0.0000

0.0000

arsenic

0.007

0.007

0.000

0.000

barium

0.18

0.18

0.00

0.00

cadmium

0.0007

0.0007

0.0000

0.0000

calcium

70

70

0

0

chromium

0.004

0.004

0.002

0.000

cobalt

0.0014

0.0014

0.0000

0.0000

copper

0.06

0.06

0.00

0.00

iron

0.6

0.6

0.0

0.0

lead

0.017

0.015

0.007

0.000

magnesium

20

18

0

9

manganese

0.04

0.03

0.00

0.02

molybdenum

0.004

0.004

0.000

0.000

nickel

0.015

0.007

0.004

0.013

potassium

5

5

0

0

sodium

170

170

0

0

strontium

0.24

0.24

0.00

0.00

uranium

0.000 26

0.000 22

0.000 14

0.000 00

vanadium

0.004

0.004

0.000

0.000

zinc

0.04

0.02

0.00

0.03

Date of issue: January 2017Date of expiry: January 2022Revised: January 2018 (Al, Ba, Mn data and acknowledgements section updated)